* BUG: *globbing* isn't performed at all, by any of the utilities
	e.g. ls -R doesn't scan directories with spaces in them
* ls doesn't skip symlinks. I should add support for that
* ls -R now works, but uses lots of memory and CPU cycles
  the fix will be to scan directories recursively, but not
  actually do recursion in C. use of a sleep function
  before each new ls() call should fix the CPU cycle issue
* cat isn't actually cat. in that, it doesn't concatenate files
	ALSO: cat cuts off some text, sha1sums don't match
	when comparing results with other cat implementations
* start making use of pledge/unveil, but only on openbsd
* test on lots of unix/unix-like operating systems
* look at https://github.com/GwenNelson/UnixPatterns
* nice shell: https://github.com/GwenNelson/face
  NOTE: no license. ask the author to add a compatible license
* return proper error codes (0 and 1 are incorrect):
  https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/errno.h.html
* take inspiration maybe from http://heirloom.sourceforge.net/
* check for possible buffer overflows, especially in head
